GRAY MATTERS 5. Butler CR, Graham KS, Hodges JR, et al. The syndrome of transient epileptic amnesia. Ann Neurol 2007;61:587–598. 6. Palmini AL, Gloor P, Jones-Gotman M. Pure amnestic seizures in temporal lobe epilepsy. Definition, clinical symptomatology and functional anatomical considerations. Brain 1992;115 (Pt 3):749–769.
DISCLOSURE None of the authors has any conflict of interest to disclose for the present publication. We confirm that we have read the Journal’s position on issues involved in ethical publication and affirm that this report is consistent with those guidelines.
Fabrice Bartolomei1 [email protected] Eve Tramoni2 Olivier Felician2 1 Clinical Neurophysiology and Epileptology Department, Timone Hospital, Marseille, France; and 2 Neurology and Neuropsychology Department, Timone Hospital, Marseille, France
In Response: Transient Epileptic Amnesia Dear Editor We thank Dr. Luders for his interest in our recent paper.1 We fully agree that the epileptic origin of acute amnestic episodes deserves further characterization. As pointed out, ictal epileptic episodes of amnesia have already been clearly documented during electroencephalography (EEG) recording in patients with “typical” temporal lobe epilepsy (TLE).2 Due to the relatively low seizure frequency in transient epileptic amnesia (TEA), only indirect evidence has so far been provided.3 All patients reported in our series were investigated in a tertiary epilepsy center, and after extensive clinical, electrophysiological, and structural and metabolic neuroimaging investigations, each was considered to have epilepsy. All (but one) of our patients exhibited awake/ sleep epileptic EEG abnormalities over temporal derivations, and most had overall good seizure outcome under antiepileptic medication. In our series, one patient was recorded during seizure, showing bitemporal ictal discharges. It is noteworthy that isolated amnestic seizures were observed in a minority of our patient series (approximately 20%), whereas the majority exhibited other clinical epileptic features, in particular suggestive of TLE (epigastric sensation, emotional changes, deja vu, and so on). Finally, secondary generalized tonic–clonic seizures occurred in a minority (approximately 10%) of them. The typical interictal cognitive profile of TEA that comprises autobiographical memory loss and accelerated rate of forgetting (ALF)4,5 was found in a subset of our patients with TEA. This profile, although suggestive of the syndrome, is thus inconstant, and has also been described in other forms of TLE.6–9 In sum, patients with TEA differ in several aspects from patients with drug-resistant mesial TLE. However, they also share many commonalities, including the following: 1. Ictal and interictal memory disturbances, that are fully coherent with the known implication of mesial temporal lobe in declarative memory; 2. Ictal symptoms that include features of mesial TLE; 3. EEG epileptic abnormalities distributed over temporal derivations. These arguments support the idea that TEA is a form of late-onset pharmacosensitive mesial TLE and, as also suggested by other authors,4,10 favor the consideration of TEA as a distinctive epileptic syndrome. The etiology of TEA remains unknown but, as suggested in our report, depression and/or autoimmune factors could be involved. Epilepsia, 55(10), 1677–1682, 2014
REFERENCES 1. Mosbah A, Tramoni E, Guedj E, et al. Clinical, neuropsychological, and metabolic characteristics of transient epileptic amnesia syndrome. Epilepsia 2014;55:699–706. 2. Palmini AL, Gloor P, Jones-Gotman M. Pure amnestic seizures in temporal lobe epilepsy. Definition, clinical symptomatology and functional anatomical considerations. Brain 1992;115(Pt 3):749–769. 3. Butler CR, Zeman AZ. Recent insights into the impairment of memory in epilepsy: transient epileptic amnesia, accelerated longterm forgetting and remote memory impairment. Brain 2008;131: 2243–2263. 4. Zeman AZ, Boniface SJ, Hodges JR. Transient epileptic amnesia: a description of the clinical and neuropsychological features in 10 cases and a review of the literature. J Neurol Neurosurg Psychiatry 1998;64:435–443. 5. Butler CR, Graham KS, Hodges JR, et al. The syndrome of transient epileptic amnesia. Ann Neurol 2007;61:587–598. 6. Blake RV, Wroe SJ, Breen EK, et al. Accelerated forgetting in patients with epilepsy: evidence for an impairment in memory consolidation. Brain 2000;123(Pt 3):472–483. 7. Viskontas IV, McAndrews MP, Moscovitch M. Remote episodic memory deficits in patients with unilateral temporal lobe epilepsy and excisions. J Neurosci 2000;20:5853–5857. 8. Tramoni E, Felician O, Barbeau EJ, et al. Long-term consolidation of declarative memory: insight from temporal lobe epilepsy. Brain 2011;134:816–831. 9. Lah S, Mohamed A, Thayer Z, et al. Accelerated long-term forgetting of verbal information in unilateral temporal lobe epilepsy: is it related to structural hippocampal abnormalities and/or incomplete learning? J Clin Exp Neuropsychol 2014;36:158–169. 10. Gallassi R, Morreale A, Di Sarro R, et al. Epileptic amnesic syndrome. Epilepsia 1992;33(Suppl. 6):S21–S25.
Commentary on IDH1 mutation is associated with seizures and protoplasmic subtype in patients with low-grade gliomas To the Editors, I have read with great interest the paper entitled “IDH1 mutation is associated with seizures and protoplasmic subtype in patients with low-grade gliomas” by Liubinas et al.1 The authors evaluated a series of 30 low-grade gliomas in order to correlate IDH1 mutation with tumor-associated epilepsy and histologic subtype. This study is very interesting; however, in my opinion some aspects of this paper are challenging.
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This document is a scanned copy of a printed document. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material.
DISCLOSURE None of the authors has any conflict of interest to disclose for the present publication. We confirm that we have read the Journal’s position on issues involved in ethical publication and affirm that this report is consistent with those guidelines.
Fabrice Bartolomei1 [email protected] Eve Tramoni2 Olivier Felician2 1 Clinical Neurophysiology and Epileptology Department, Timone Hospital, Marseille, France; and 2 Neurology and Neuropsychology Department, Timone Hospital, Marseille, France
In Response: Transient Epileptic Amnesia Dear Editor We thank Dr. Luders for his interest in our recent paper.1 We fully agree that the epileptic origin of acute amnestic episodes deserves further characterization. As pointed out, ictal epileptic episodes of amnesia have already been clearly documented during electroencephalography (EEG) recording in patients with “typical” temporal lobe epilepsy (TLE).2 Due to the relatively low seizure frequency in transient epileptic amnesia (TEA), only indirect evidence has so far been provided.3 All patients reported in our series were investigated in a tertiary epilepsy center, and after extensive clinical, electrophysiological, and structural and metabolic neuroimaging investigations, each was considered to have epilepsy. All (but one) of our patients exhibited awake/ sleep epileptic EEG abnormalities over temporal derivations, and most had overall good seizure outcome under antiepileptic medication. In our series, one patient was recorded during seizure, showing bitemporal ictal discharges. It is noteworthy that isolated amnestic seizures were observed in a minority of our patient series (approximately 20%), whereas the majority exhibited other clinical epileptic features, in particular suggestive of TLE (epigastric sensation, emotional changes, deja vu, and so on). Finally, secondary generalized tonic–clonic seizures occurred in a minority (approximately 10%) of them. The typical interictal cognitive profile of TEA that comprises autobiographical memory loss and accelerated rate of forgetting (ALF)4,5 was found in a subset of our patients with TEA. This profile, although suggestive of the syndrome, is thus inconstant, and has also been described in other forms of TLE.6–9 In sum, patients with TEA differ in several aspects from patients with drug-resistant mesial TLE. However, they also share many commonalities, including the following: 1. Ictal and interictal memory disturbances, that are fully coherent with the known implication of mesial temporal lobe in declarative memory; 2. Ictal symptoms that include features of mesial TLE; 3. EEG epileptic abnormalities distributed over temporal derivations. These arguments support the idea that TEA is a form of late-onset pharmacosensitive mesial TLE and, as also suggested by other authors,4,10 favor the consideration of TEA as a distinctive epileptic syndrome. The etiology of TEA remains unknown but, as suggested in our report, depression and/or autoimmune factors could be involved. Epilepsia, 55(10), 1677–1682, 2014
REFERENCES 1. Mosbah A, Tramoni E, Guedj E, et al. Clinical, neuropsychological, and metabolic characteristics of transient epileptic amnesia syndrome. Epilepsia 2014;55:699–706. 2. Palmini AL, Gloor P, Jones-Gotman M. Pure amnestic seizures in temporal lobe epilepsy. Definition, clinical symptomatology and functional anatomical considerations. Brain 1992;115(Pt 3):749–769. 3. Butler CR, Zeman AZ. Recent insights into the impairment of memory in epilepsy: transient epileptic amnesia, accelerated longterm forgetting and remote memory impairment. Brain 2008;131: 2243–2263. 4. Zeman AZ, Boniface SJ, Hodges JR. Transient epileptic amnesia: a description of the clinical and neuropsychological features in 10 cases and a review of the literature. J Neurol Neurosurg Psychiatry 1998;64:435–443. 5. Butler CR, Graham KS, Hodges JR, et al. The syndrome of transient epileptic amnesia. Ann Neurol 2007;61:587–598. 6. Blake RV, Wroe SJ, Breen EK, et al. Accelerated forgetting in patients with epilepsy: evidence for an impairment in memory consolidation. Brain 2000;123(Pt 3):472–483. 7. Viskontas IV, McAndrews MP, Moscovitch M. Remote episodic memory deficits in patients with unilateral temporal lobe epilepsy and excisions. J Neurosci 2000;20:5853–5857. 8. Tramoni E, Felician O, Barbeau EJ, et al. Long-term consolidation of declarative memory: insight from temporal lobe epilepsy. Brain 2011;134:816–831. 9. Lah S, Mohamed A, Thayer Z, et al. Accelerated long-term forgetting of verbal information in unilateral temporal lobe epilepsy: is it related to structural hippocampal abnormalities and/or incomplete learning? J Clin Exp Neuropsychol 2014;36:158–169. 10. Gallassi R, Morreale A, Di Sarro R, et al. Epileptic amnesic syndrome. Epilepsia 1992;33(Suppl. 6):S21–S25.
Commentary on IDH1 mutation is associated with seizures and protoplasmic subtype in patients with low-grade gliomas To the Editors, I have read with great interest the paper entitled “IDH1 mutation is associated with seizures and protoplasmic subtype in patients with low-grade gliomas” by Liubinas et al.1 The authors evaluated a series of 30 low-grade gliomas in order to correlate IDH1 mutation with tumor-associated epilepsy and histologic subtype. This study is very interesting; however, in my opinion some aspects of this paper are challenging.
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This document is a scanned copy of a printed document. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material.
